This invention relates to blind riveting, that is, riveting performed from a single side of a workpiece assembly. In particular, the invention pertains to loose application of blind rivets to an assembly.
It is known in the art relating to riveting to apply blind rivets from a single side of a workpiece assembly of two or more components. In the assembly process, holes are formed in the components, which are placed in engagement with the holes aligned to receive the hollow body of a blind rivet having a preformed head at one end. The rivet includes a mandrel with a stem extending through the hollow body and an enlarged end engaging a headless (blind) end of the body.
The rivet is held by a rivet gun with the stem of the mandrel inserted into an opening in a nose of the gun and the outer head of the rivet against the nose. The body of the rivet is inserted fully into the aligned holes in the components, and the gun is actuated to draw the mandrel outward through the preformed head. The enlarged end of the mandrel deforms the blind end of the body to create a blind head that pulls the components together and expands the body to fill the aligned holes while the nose of the gun forces the outer head against the adjacent component of the assembly. The result is a riveted joint that maintains the components in tightly fixed assembly.
FIGS. 1-3 illustrate steps in the prior art setting or application of one of the many forms of blind rivets to fix together two components of a component assembly 10. FIG. 1 shows a blind rivet 12 having a hollow body 14 with a preformed head 16 at one end. A mandrel 18 has a stem 20 connecting with an enlarged end 22 forming a conical wedge engaging the blind end 23 of the body 14 opposite from the head 16. The body 14 is shown inserted through aligned holes 24, 26, respectively, in adjacent components 28, 30 of the assembly. The rivet head is engaged by a nose 32 of any form of rivet gun or setting apparatus, not further illustrated. The components 28, 30 are shown spaced apart for clarity but would preferably be placed in engagement adjacent the holes 24, 26 prior to setting the rivet. The rivet gun includes mechanism, not shown, that grips the stem 20 of the mandrel for subsequently drawing the enlarged end outward in the direction of the rivet head 16.
FIG. 2 shows the assembly 10 after actuation of the rivet gun to set the rivet 12. The enlarged end 22 of the mandrel 18 has been drawn into the hollow body 14 of the rivet 12, enlarging the blind end 23 of the rivet against the distal component 30 and expanding the body to fill the holes 24, 26 while the nose 32 of the rivet gun remains against the preformed head 16 of the rivet, forcing the head against the adjacent component 28.
In FIG. 3, the stem 20 has been broken off flush with the rivet head and removed with the rivet gun nose 32, leaving the remainder of the mandrel 18 fixed to the interior of the hollow rivet body 14 while the body has been expanded into engagement with the aligned holes 24, 26. The head 16 remains in engagement with the adjacent component 28 while the enlarged blind end 23 engages the distal component 30, thereby holding the components 28, 30 in fixed engagement.
In a particular application, hydroformed frame components are held in pre-assembly by blind rivets prior to welding into a strong frame assembly. However, the riveted joints may be too constrained to accommodate variations in the parts that require adjustment of the joint connections to meet dimensional requirements of the frame prior to welding.
The present invention provides a method and apparatus for loosely attaching blind rivets to components of an assembly. The method includes attaching a rivet to an assembly while positioning the head at a predetermined clearance away from the adjacent one of the assembly components. One or both of aligned openings in the components may also be enlarged to leave radial clearance between the assembled rivet body and the enlarged openings.
The apparatus includes a nose insert for use with or attachment to a rivet gun or attaching apparatus. The insert is formed as a member having a hollow center for receiving the stem of a mandrel or the nose of a conventional rivet gun. The member includes a first portion engageable with an associated rivet gun, a second portion engageable by a preformed rivet head, and a third portion engageable with a component adjacent to the rivet head and configured to maintain a predetermined clearance between the rivet head and the component when the rivet head is engaging the second portion.
These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.